Causes of Small Cell Lung Cancer

OncoLink Team
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: May 7, 2013

Question

My spouse recently passed away from lung cancer at the age of 43. He was a smoker for many years. I understand that small cell cancer is microscopic. Are there any findings that small cell lies dormant? I am trying to understand why the small cell cancer all of a sudden developed in my spouse. Could some exposure, either recent or from his past, other than the smoking have triggered it?

Answer

Barbara Campling, MD, Medical Oncologist, responds:

I am very sorry for your loss. Your husband was relatively young to be diagnosed with this type of cancer. Small cell lung cancer got its name because the cells, which make up the tumor, appear small under the microscope, when compared to the other types of lung cancer, which are collectively called non-small cell lung cancer. This doesn't necessarily mean that the tumors, which are composed of these cells, are small or microscopic. The diagnosis is made by a pathologist who looks at the tumor under a microscope. However, this does not mean that the tumors are microscopic. Small cell lung cancer tends to grow and spread more rapidly than the other types of lung cancer. The rate of growth can sometimes be quite alarming. On the other hand, it also tends to respond better to chemotherapy and radiation therapy than non-small cell lung cancer. Almost all cases of small cell lung cancer occur in people who have smoked for many years. Other exposures, such as radon or asbestos, may also contribute in some cases.

The question of whether small cell lung cancer can lie dormant for a period of time is an interesting one. It is likely that the genetic damage to the airways, which eventually leads to lung cancer, has been present for many years before diagnosis. However, generally speaking, once a small cell lung cancer has started to grow, it will continue to grow. Because of the rapid rate of growth, symptoms can come on quite acutely. Chemotherapy usually causes the tumor to shrink down, and when it does, it can often remain "in remission." Unfortunately, except in some cases where the tumor is confined to the chest, the tumor eventually starts to grow again, and then it usually does not respond as well to chemotherapy as it did at during the first course of treatment.